There is a way to play TCE as a non admin, though it requires an admin account to set it up:
1) Go to Control Panel => Administrative Tools => Local Security Policy. This will open up the Local Security setting window.
2) Expand the Local Policies folder and select, User Rights Assignment. This will bring up a list of security settings for the computer. You will need to add the user that will be launching the game to have the following privileges.
3) If the user is logged in while making changes, the user must be logged out and back in for the changes to take effect.
Load and unload device drivers
Manage auditing and security log
Modify Firmware environment values
Profile Single Process
An example Screenshot
This is done by double clicking on the setting and then the "Add User or Group" button. You can either type the user or group name into the field or click on "advanced" to select from a list. If you select advanced, you may need to click on the "Object Types" button and make sure all 3 boxes are checked. Then click "OK". Click on the "Find Now" button to generate a full list of all users and groups on the system.
Highlight the user you want to add the rights to and click "OK". Keep clicking "OK" untill you are back at the Local Security Settings window. Repeat this process for the rest of the list. That user will now be able to play on PB servers without getting kicked for "Inadequate O/S Privileges".
Post if you have any problems